Cost. Ballparking from memory (because I'm on mobile) sending something to space on the Space Shuttle cost something like $40k/kg. The Falcon brought that down

Cost. Ballparking from memory (because I'm on mobile) sending something to space on the Space Shuttle cost something like $40k/kg. The Falcon brought that down to 2500, and the Falcon Heavy down to just over $1k/kg. So nearly two orders of magnitude cheaper, but you still can't really do anything too fun in space at $1k/kg. The goal with Starship (and its rapid reuse) is to bring costs down another couple of orders of magnitude to where we could eventually even see costs drop into the single digit per kg. And at that point suddenly space becomes open to things that sound difficult to even fantasize about today, like colonizing Mars, taking suborbital flights to get from Texas to Hong Kong, or setting up industrial systems on the Moon, to say nothing of space tourism that doesn't start with the prerequisite of being a billionaire.